Current perspectives on novel systemic therapeutic agents beyond immune checkpoint inhibition in metastatic urothelial carcinoma

Treatment strategies for metastatic urothelial carcinoma (mUC) have evolved dramatically over the last decade. The emergence of immunotherapeutic agents, especially immune checkpoint inhibitors, has been the most significant development. Immunotherapy increased the overall survival rate of patients with mUC and provided a durable response. The success of immune checkpoint inhibitors further led to the development of novel agents that regulate the immune system within the tumor microenvironment. However, despite some success with immune checkpoint inhibitors, researchers are still developing new agents, including small molecule tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and novel fusion proteins, tailored for targets other than immune checkpoint inhibitors. Novel treatment strategies are being developed rapidly with ongoing pre-clinical trials. Here, we outline promising new therapies that are expected to improve survival rates for patients with mUC.